johnhw

# This implements the ideas in the paper "Neural Ordinary Differential Equations"
# in as simple a form as possible, using only autograd. It is not efficient.
# It is not useful for any practical purpose. 
# Use [torchdiffeq](https://github.com/rtqichen/torchdiffeq) for any real use.
#
# > [1] Ricky T. Q. Chen, Yulia Rubanova, Jesse Bettencourt, David Duvenaud. 
# "Neural Ordinary Differential Equations." *Advances in Neural Processing Information Systems.* 2018. 
# [[arxiv]](https://arxiv.org/abs/1806.07366)
#
# The implementation is based on the 

johnhw

johnhw

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from collections import defaultdict
import colorsys
import munkres  # provides Hungarian algorithm
import scipy.spatial.distance as dist
import functools
import os

johnhw

from tqdm.auto import trange, tqdm
def tqdm_train_loop(train_fn, num_epochs, train_loader, val_fn=None):
    # each epoch
    with trange(num_epochs, unit="epoch") as epoch_t:
        for epoch in epoch_t:
            # each batch
            with tqdm(train_loader, leave=False, unit='batch', postfix='') as batch_t:
                for batch_idx, (features, targets) in enumerate(batch_t):
                    cost = train_fn(features, labels)
                    batch_t.postfix = f"cost {cost.item():.2f}"

johnhw

import numpy as np

def softmax(a,b):
    return np.log(np.exp(a)+np.exp(b))

def softmin(a,b):
    return -softmax(-a, -b)

def softrank(a, b):
    return softmin(a,b), softmax(a,b)

johnhw

import inspect



class tracked:
    """Class to remember the execution frame
    that a function call was made in."""
    def __init__(self, fn):
        self.fn = fn
                        

johnhw

# bivariate colormaps in matplotlib
import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt


## Bivariate colormapping
from scipy.interpolate import RegularGridInterpolator

johnhw

from matplotlib.collections import LineCollection

def plot_connected_pairs(a,b,*args,**kwargs):
    """
    Draw lines between two arrays of 2D points.
    a and b must be the same shape, both [N,2] arrays to be plotted.
    
    Parameters:
    -----------
    a:  [N,2] array of points to plot from

johnhw

import numpy as np
from sklearn.metrics import confusion_matrix
from collections import defaultdict


def itr(confusion_matrix, timings, eps=1e-8):
    """Take a confusion matrix of the form
                     (actual) a   b   c   d 
    (intended)                
         a                     10  0   1   9

johnhw

# Converts Ordnance Survey Terrian 50 United Kingdom data to a simple NumPy array of terrain altitudes
# The original OS data is freely downloadable from: https://www.ordnancesurvey.co.uk/business-government/products/terrain-50
# Directly converts the zipped terrain file to a NPZ file
# Resulting array is a (24600, 13200) array of float64 
# Requirements:
# * pycrs 
# * lxml 


import os, sys